div{
    height: 400px;
    width: 100%;
}
ul{
    padding: 0;
    margin: 0;
}
ul li{
    height: 20px;
    width: 24%;
    color: #fff;
    float: left;
    display: inline;
    border-right: 1px solid #ccc;
    border-bottom: 1px solid #ccc;
    background-color: rgb(29, 21, 10);
}
ul li:hover{
    background: #456;
}
ul li ul{
    visibility: hidden;

}
ul li:hover ul{
    visibility: visible;
}
ul li ul li{
    width: 100%;
    display: inline;
    list-style: none;
}